Is there any way to increase the KVM?

[Hugo Silva]

Pawel Jakub Dawidek wrote:
> On Thu, Jun 05, 2008 at 01:53:37AM +0800, Tz-Huan Huang wrote:
>   
>> On Thu, Jun 5, 2008 at 12:31 AM, Dag-Erling Sm??rgrav <des at des.no> wrote:
>>     
>>> "Tz-Huan Huang" <tzhuan at csie.org> writes:
>>>       
>>>> The vfs.zfs.arc_max was set to 512M originally, the machine survived for
>>>> 4 days and panicked this morning. Now the vfs.zfs.arc_max is set to 64M
>>>> by Oliver's suggestion, let's see how long it will survive. :-)
>>>>         
>>> des at ds4 ~% uname -a
>>> FreeBSD ds4.des.no 8.0-CURRENT FreeBSD 8.0-CURRENT #27: Sat Feb 23 01:24:32 CET 2008     des at ds4.des.no:/usr/obj/usr/src/sys/ds4  amd64
>>> des at ds4 ~% sysctl -h vm.kmem_size_min vm.kmem_size_max vm.kmem_size vfs.zfs.arc_min vfs.zfs.arc_max
>>> vm.kmem_size_min: 1,073,741,824
>>> vm.kmem_size_max: 1,073,741,824
>>> vm.kmem_size: 1,073,741,824
>>> vfs.zfs.arc_min: 67,108,864
>>> vfs.zfs.arc_max: 536,870,912
>>> des at ds4 ~% zpool list
>>> NAME                    SIZE    USED   AVAIL    CAP  HEALTH     ALTROOT
>>> raid                   1.45T    435G   1.03T    29%  ONLINE     -
>>> des at ds4 ~% zfs list | wc -l
>>>     210
>>>
>>> Haven't had a single panic in over six months.
>>>       
>> Thanks for your information, the major difference is that we
>> runs on 7-stable and the size of our zfs pool is much bigger.
>>     
>
> I'm don't think the panics are related to pool size. More to the load
> and characteristics of your workload.
>
>   
>> root at cml2$ uname -a
>> FreeBSD cml2.csie.ntu.edu.tw 7.0-STABLE FreeBSD 7.0-STABLE #40: Sat
>> May 31 10:29:16 CST 2008
>> root at cml2.csie.ntu.edu.tw:/usr/local/obj/usr/local/src/sys/CML2  amd64
>> root at cml2$ sysctl -h vm.kmem_size_min vm.kmem_size_max vm.kmem_size
>> vfs.zfs.arc_min vfs.zfs.arc_max
>> vm.kmem_size_min: 0
>> vm.kmem_size_max: 1,610,612,736
>> vm.kmem_size: 1,610,612,736
>> vfs.zfs.arc_min: 16,777,216
>> vfs.zfs.arc_max: 67,108,864
>> root at cml2$ zpool list
>> NAME                    SIZE    USED   AVAIL    CAP  HEALTH     ALTROOT
>> sun                    11.3T   9.03T   2.30T    79%  ONLINE     -
>> root at cml2$ zfs list | wc -l
>>      295
>>     
>
> If we're comparing who has bigger... :)
>
> beast:root:~# zpool list
> NAME                    SIZE    USED   AVAIL    CAP  HEALTH     ALTROOT
> tank                    732G    604G    128G    82%  ONLINE     -
>
> but:
>
> beast:root:~# zfs list | wc -l
>     1932
>
> No panics.
>
> PS. I'm quite sure the ZFS version I've in perforce will fix most if not
> all 'kmem_map too small' panics. It's not yet committed, but I do want
> to MFC it into RELENG_7.
>
>   

Any guesstimate as to when the MFC will happen ?